Multiple unit well bore sidewall sampler tool

ABSTRACT

A well bore sidewall-sampling tool comprises a casing, adapted to be secured to the end of a drill pipe, and containing a plurality of sample core cutter heads, each of which encases a clear plastic disposable liner tube for receiving and protecting a collected sample of the well bore wall. An actuating mechanism within the casing is operated by fluid pressure applied through the drill pipe. This mechanism includes a rigid operating bar connected to each head for moving each cutter head outwardly into sampling engagement with the sidewall of the well bore when fluid pressure is applied to the casing. The drill pipe is then lifted to cause the heads to bite into the sidewall and cut a sample. A compression spring retracts the sample heads into the casing when the sampling operation is completed.

United States Patent Inventor Luther Ballard Appl. No. 20,655

Filed Mar. 18, I970 Patented Aug. 10, 1971 Assignee Slimhole SampleService m. y

MULTIPLE UNIT WELL BORE SIDEWALL SAMPLER TOOL 8 Claims, 2 Drawing Figs.

US. Cl 1175/77 lnt. E2lb49/02 Field olSeer-ch 175/77,58, 202, 203

Relerenea Cited UNITED STATES PATENTS 2,013,457 9/1935 Burt 175/778/1943 Spencer 175/77 X Primary Examiner-lan A. Calvert AssistantExaminerRichard E. Favreau Attorney-Drake and Crandell ABSTRACT: A wellbore sidewall-sampling tool comprises a casing, adapted to be secured tothe end of a drill pipe, and containing a plurality of sample corecutter heads, each of which encases a clear plastic disposable linertube for receiving and protecting a collected sample of the well borewall. An actuating mechanism within the casing is operated by fluidpressure applied through the drill pipe. This mechanism includes a rigidoperating bar connected to each head for moving each cutter headoutwardly into sampling engagement with the sidewall of the well borewhen fluid pressure is applied to the casing. The drill pipe is thenlifted to cause the heads to bite into the sidewall and cut a sample. Acompression spring retracts the sample heads into the casing when thesampling operation is completed.

PATENTED mm 0 I97! INVENTOR [QJTHER BULLARD @fiahu ATTORNEYS MULTIPLEUNIT WELL BORE SIDEWALL SAMPLER TOOL FIELD OF THE INVENTION The presentinvention relates to an improved sidewall sampler tool forsimultaneously obtaining a plurality of wall samples from well bores.

The present invention constitutes an improvement on the well boresidewall sampler tool disclosed in applicants copending application Ser.No. 889,090, filed Dec. 30, I969, for WELL BORE SIDEWALL SAMPLER TOOL.To the extent necessary for a complete understanding of the withindescribed invention, the disclosure of said copending application isincorporated by reference herein. In summary, the invention disclosed inthat application embodies an improved sidewall sampler tool adapted tobe secured on the lower end of a drill pipe. The sampler tool includes atubular casing having a core cutter head pivotally mounted therein. Aflexible sample collection receptacle is provided on one end of the corecutter head, while the opposite end of the head includes a spadelikesharpened cutting edge. The core cutter head is actuated to swingoutwardly of the easing into sampling engagement with the wall of a wellbore by means of a piston and linkage mechanism actuated by theapplication of fluid pressure to the casing through the drill pipe. Theactuating mechanism includes a piston slidably mounted within the easingand biased towards its upper position by a retracting spring. The pistonis connected to the core cutter head by a linkage which, when the pistonis moved downwardly under the influence of the fluid pressure, swingsthe core cutter head outwardly into sampling engagement with the wall ofthe well bore. When the cutter head is extended, the drill pipe stem isthen lifted to pull on the sampling tool and cause the core head to diga sample from the sidewall of the well bore. The sample is collected andretained in the receptacle for later analysis. For a more completedescription of the aforesaid apparatus, reference should be made to theaforesaid application.

Various types of multiple unit sample-coring devices have been shown inthe art. See, for example, U.S. Pat. No. 2,500,l25, issued Mar. 7, 1950,to T. A. Huber for Sidewall Coring Device"; U.S. Pat. No. 2,334,428,issued Nov. 16, 1943, to L. C. Miller for Well Device; U.S. Pat. No.2,299,076, issued Oct. 20, l942, to P. T. Bynum for Sidewall Sampler";U.S. Pat. No. 2,044,648, issued June 16, 1936, to, H. F. Stevens forSidewall Formation Sampler"; and U.S. Pat. No. 2,013,457, issued Sept.3, 1935, to C. E. Burt for Apparatus for Extracting Cores from theSidewall of Well Bores.

OBJECTS OF THE INVENTION It is the principal object of the presentinvention to provide an improved multiple core unit sidewall samplertool which is adapted to give substantial representative samples of thematerial through which the drill hole passes.

Another object of the present invention is to provide a multiple unittool of the foregoing character which produces a positive samplingaction, and in which the sample collected is protected against loss orcontamination.

A further object of the present invention is to provide a multiple coreunit sample tool in which core-sampling units can be added to or removedfrom the sampler tool in order to achieve the desired representativesamples.

Other objects and advantages of the present invention will becomeapparent from the following drawings and description of the invention.

SUMMARY OF THE INVENTION The foregoing objects are accomplished by animproved multiple core unit sidewall sampler tool adapted to be securedon the lower end ofa drill pipe. The sampler tool includes a tubularcasing having pivotally mounted therein a plurality of core samplertubes. These tubes are simultaneously actuated to swing outwardly andinwardly of the casing. A power device such as a piston and cylindermechanism, is coupled to the various cutter units by means of a singlerigid linkage system. Upon actuation of the power device, the linkagesystem swings the cutter tubes outwardly of the easing into samplingengagement with the well bore sidewall. When the cutter heads areextended, the drill pipestem is lifted to pull on the sampling tool andcause the core heads to dig samples from the sidewall of the well bore.These samples are collected in individual removable collection tubeshoused within each cutter head. The sample cutter heads are thenretracted by a spring or other appropriate device mounted within thecasing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is an elevation view of amultiple core unit sidewall sampler tool embodying the presentinvention, with the casing in section to reveal the internal cutter headand linkage mechanism.

FIG. 2 is a view similar to FIG. 1 but substantially enlarged, withportions of the cutter tube mechanism in section, and furtherillustrating the cutter heads as extended into sampling position.

DESCRIPTION OF THE PREFERRED EMBODIMENT The multiple unit sidewallsampler tool embodying the present invention shown in the drawingcomprises a tubular casing 10 housing the samplecutting heads 11 andactuating mechanism indicating generally at 12. The casing is internallythreaded at its upper end and adapted to be secured to the lower end ofa drill pipestem I4 by an appropriate coupling connector 15. Atits lowerend, the casing is enclosed by a bull plug 16. In the embodiment shown,four individual cutter heads II are provided. It will be understood bythose skilled in the an that additional heads may be utilized, inkeeping with the principal objective of the invention, in order toprovide a multiple sampling action. The casing 10, when secured to thelower end of a drill pipestem I4 is lowered into a well bore, indicatedgenerally at 18, for obtaining sidewall samples from the material 19forming the walls of the bore 18.

The sample cutter heads II are identical, and each sample cutter headcomprises a tubular member 20 and a base member 21. The base member 21is pivotally mounted within the casing 10. A generally rectangularopening 22 is provided in the casing corresponding to each cutter headunit 11, and adjacent to which'the respective cutter head is mounted.For supporting the tubular member 20, each base member 21 is providedwith a boss or projection 24 adapted to fit snugly within and supportthe tubular member or sample tube 20. At its upper end, the tube 20 isprovided with a cutting edge 25 for digging a sample from the wall ofthe well bore. For receiving this sample, a stiff plastic tubularreceptacle 26 is inserted and housed within the bore 28 of the tube 20.The bore 28 terminates, at the upper end of the member 20 in acounterbore 29, thereby defining a shoulder 30 against which the upperend of the plastic receptacle 26 seats. The lower end of the plasticreceptacle 26 is closed so as to form a cylindrical container which maybe readily removed from the tube 20 for retaining and protecting thesample for later analysis.

For swinging the sample cutter heads II in and out of the casing throughthe openings 22 defined therein, an actuating mechanism [2 is provided.This mechanism is operated to position the cutter beads by any suitablemeans, one illustrative means shown comprising a fluid pressure systemapplied to the casing l0 through the drill pipe II. For example,hydraulic fluid pressure in the range of I400 p.s.i. is applied throughthe drill pipe to the casing to actuate the sampling mechanism. Thecutter headactuating mechanism 12 comprises a piston 32 slidably mountedwithin the casing 10 and having a pair of spaced O-rings or similar sealring members 34 sealingly engaging the internal surface of the casing10.

The piston 32 is positioned within the casing above the cutter heads 11and includes a depending stem 35 which is coupled to a rigid elongatedoperating bar 36. The operating bar 36 extends throughout substantiallythe length of the casing l0, and includes elemental sections 38corresponding to each of the cutter heads 11 joined by lateral sections39. The respective elemental sections 38 of the operating bar 36 areradially and axially offset to provide space for receiving the cutterheads 11. Also, this structure affords a single rigid operating barwhich serves to actuate simultaneously all of the heads inwardly oroutwardly of the casing.

Each cutter head is operatively connected with the operating bar 36 byan elongated link 44. The link 44 is pivoted at one end to the adjoiningelemental section 38 of the operating bar 36, and at its other end ispivotallyjoined to a rib 45 on the tube of each cutter head.

Provision is made to control movement of the operating bar and therebydetermine the extent of outward movement of the cutter head 11 from thecasing 10. At its lower end, the operating bar 36 includes a lateralsection 39 provided with a depending arm 40 adapted to engage the end ofa stop screw 41 threadably engaged in the lower tip end of the bull plug16 and extending axially within the casing. In order to lift theoperating bar 36 to retract the cutter heads, a coil spring 42 surroundsthe pin 40 and screw 41 and acts between the bull plug 16 and lateralsection 39. When pressure on the piston is released, the spring 42 liftsthe operating bar 36, and as will be described below, effects theretraction of the cutter heads ll into the casing.

Prior to the operation of the sampler tool, each cutter head tube 20 isremoved from its pivotal mounting member 21, and a plastic samplereceptacle 26 is inserted therein. The link 44 provides sufficient slackso that the tubes 20 may be slipped off of their mounting members 21 andreadily be thereon replaced. The adjusting screw 41 is then set toprovide for the desired extension of the cutter heads ll outwardly fromthe casing. The casing, with the assembled cutter heads 11 is secured toone end ofa drill pipestem l4 and lowered into the well bore 18 to besampled. When the desired level is reached for sampling, pressure fluidis supplied through the drill pipestem l4 and acts on the piston 32,pushing the same downwardly. Downward movement of the piston 32 movesthe operating bar 36 downwardly until the arm 40 thereon engages theadjusting screw 4l. During this downward movement, the links 44 swingthe cutter heads 11 outwardly of the easing into engagement with thesidewall 19 of the well bore 18. The operator then pulls the drill stem14 upwardly a few inches, during which movement the cutting edge of thecutter heads 11 digs into the well sidewalls l9 and removes a samplewhich is collected within the sample receptacle 26. When the samplinghas been completed, the drill pipe is lowered slightly, fluid pressureis released, and excess pressure fluid escapes through a vent hole 48 inthe casing l0. The spring 42 urges the operating bar 36 and piston 32upwardly, and thereby retracts the cutter heads 11 into the casing 10.The unit can then be removed from the well. Each cutter head tube 20 isthen removed, and the sample-containing plastic receptacle 26 are takenout for analysis.

While a certain illustrative embodiment of the present invention hasbeen shown in the drawing and described above in considerable detail. ltshould be understood that there is no intention to limit the inventionto the specific form disclosed. On the contrary, the intention is tocover all modifications, alternative constructions, equivalents and usesfalling within the spirit and scope of the invention as expressed in theappended claims.

lclaim:

l. A well bore sidewall-sampling tool for use on a drill pipe forobtaining sidewall samples from a well bore, comprising a tubular casingadapted to be secured to the end of the drill pipe, a plurality ofelongated tubular sample cutter heads swingably mounted at their lowerends in said casing in alternateg opposed positions therein and adaptedto be swun outwar ly t rough corresponding openings efined in the wa ofsaid casing for digging a sample from the sidewall of the well bore andto be retracted inwardly through said openings upon the completion ofsaid sampling, and means including a power source for positivelyextending said cutter heads outwardly from said casing to engage thesidewall of the well bore and dig samples therefrom as the drill pipe islifted upwardly within the well, characterized by the inclusiontherewith of a rigid operating bar longitudinally disposed in saidcasing and having alternately spaced elemental sections and lateralsections, each elemental section corresponding to a cutter head, andlink means operatively connecting each said elemental section with theupper end of a corresponding cutter head whereby axial movement of saidbar effects simultaneous outward or inward swinging movement of saidcutter heads through the corresponding casing openings.

2. A sampling tool as defined in claim 1 wherein said power meanscomprises a fluid pressure source and a piston slidably mounted withinsaid casing and means operatively connecting said piston with saidoperating bar.

3. A sampling tool as defined in claim 1 including spring means betweenthe lower end of said casing and lower end of said bar for lifting saidbar to retract the cutter heads operatively connected therewith.

4. A sampling tool as defined in claim 1 wherein each said cutter headincludes a clear plastic disposable liner removably mounted therein forreceiving and protecting a sidewall sample.

5. In a well bore sidewall-sampling tool for use on a drill pipe forobtaining sidewall samples from a well bore and comprising a tubularcasing adapted to be secured to the end of the drill pipe, a pluralityof sample cutter heads mounted in said casing and adapted to extendoutwardly therefrom through openings defined in the wall of said casingfor digging samples from the sidewall of the well bore, means forpositively extending said cutter heads outwardly from said casing andmeans within said casing for positively retracting said cutter heads,the combination therewith of a rigid elongated operating barlongitudinally disposed within said casing and having alternately spacedelemental sections and lateral sections, each said elemental sectionhaving a cutter head associated therewith, link means operativelyconnecting each said elemental section with said associated cutter head,means operatively connecting the upper end of said bar with saidextending means, and means operatively connecting the lower end of saidbar with said retracting means, whereby axial movement of said bareffects simultaneous outward or inward swinging movement of said cutterheads with respect to said casing.

6. The well bore sidewall-sampling tool as defined in claim 5 whereinsaid means for positively extending said cutter heads outwardly fromsaid casing comprises a piston slidably and sealingly mounted withinsaid casing and a source of fluid pressure for applying fluid pressurethrough the drill pipe to said piston and thereby drive said operatingbar axially within said casing to swing the cutter heads outwardly ofthecasing.

7. The well bore sidewall-sampling tool as defined in claim 5 whereinsaid means for positively retracting said cutter heads comprises aspring means acting between the lower end of said casing and saidoperating bar for lifting said bar and thereby retracting said cutterheads.

8. The well bore sidewall sampling tool as defined in claim 5 includingadjustable stop means mounted in the lower end of said casing forlimiting engagement with said operating bar to limit the axial movementthereof and thereby adjustably limiting the outward swinging movement ofsaid cutter heads from said Casing.

1. A well bore sidewall-sampling tool for use on a drill pipe forobtaining sidewall samples from a well bore, comprising a tubular casingadapted to be secured to the end of the drill pipe, a plurality ofelongated tubular sample cutter heads swingably mounted at their lowerends in said casing in alternately opposed positions therein and adaptedto be swung outwardly through corresponding openings defined in the wallof said casing for digging a sample from the sidewall of the well boreand to be retracted inwardly through said openings upon the completionof said sampling, and means including a power source for positivelyextending said cutter heads outwardly from said casing to engage thesidewall of the well bore and dig samples therefrom as the drill pipe islifted upwardly within the well, characterized by the inclusiontherewith of a rigid operating bar longitudinally disposed in saidcasing and having alternately spaced elemental sections and lateralsections, each elemental section corresponding to a cutter head, andlink means operatively connecting each said elemental section with theupper end of a corresponding cutter head whereby axial movement of saidbar effects simultaneous outward or inward swinging movement of saidcutter heads through the corresponding casing openings.
 2. A samplingtool as defined in claim 1 wherein said power means comprises a fluidpressure source and a piston slidably mounted within said casing andmeans operatively connecting said piston with said operating bar.
 3. Asampling tool as defined in claim 1 including spring means between thelower end of said casing and lower end of said bar for lifting said barto retract the cutter heads operatively connected therewith.
 4. Asampling tool as defined in claim 1 wherein each said cutter headincludes a clear plastic disposable liner removably mounted therein forreceiving and protecting a sidewall sample.
 5. In a well boresidewall-sampling tool for use on a drill pipe for obtaining sidewallsamples from a well bore and comprising a tubular casing adapted to besecured to the end of the drill pipe, a plurality of sample cutter headsmounted in said casing and adapted to extend outwardly therefrom throughopenings defined in the wall of said casing for digging samples from thesidewall of the well bore, means for positively extending said cutterheads outwardly from said casing and means within said casing forpositively retracting said cutter heads, the combination therewith of arigid elongated operating bar longitudinally disposed within said casingand having alternately spaced elemental sections and lateral sections,each said elemental section having a cutter head associated therewith,link means operatively connecting each said elemental section with saidassociated cutter head, means operatively connecting the upper end ofsaid bar with said eXtending means, and means operatively connecting thelower end of said bar with said retracting means, whereby axial movementof said bar effects simultaneous outward or inward swinging movement ofsaid cutter heads with respect to said casing.
 6. The well boresidewall-sampling tool as defined in claim 5 wherein said means forpositively extending said cutter heads outwardly from said casingcomprises a piston slidably and sealingly mounted within said casing anda source of fluid pressure for applying fluid pressure through the drillpipe to said piston and thereby drive said operating bar axially withinsaid casing to swing the cutter heads outwardly of the casing.
 7. Thewell bore sidewall-sampling tool as defined in claim 5 wherein saidmeans for positively retracting said cutter heads comprises a springmeans acting between the lower end of said casing and said operating barfor lifting said bar and thereby retracting said cutter heads.
 8. Thewell bore sidewall sampling tool as defined in claim 5 includingadjustable stop means mounted in the lower end of said casing forlimiting engagement with said operating bar to limit the axial movementthereof and thereby adjustably limiting the outward swinging movement ofsaid cutter heads from said casing.